In designing a high-availability e-commerce site, you must investigate every component's subsystems and find the one critical piece that could bring your entire system to a screeching halt. Any downtime is unacceptable. This RFP focuses primarily on Layer 4 appliances, such as Intel Corp.'s e-Commerce Directory 7180 and RadWare's WSD-Pro, as well as on switches such as Foundry Networks' ServerIronXL and Enterasys Networks' SmartSwitch Router 8600. Such devices are dedicated to ensuring availability of services on the wire at the application level, by monitoring resources and protocols.

Your e-commerce infrastructure will likely include devices that can monitor servers and services individually. They'll be able to route incoming traffic to the most appropriate server and, when necessary, make their way around downed servers and services. These load-balancing products have grown into a white-hot portion of the Internet traffic-management space and are an important element of this RFP.

We asked 10 vendors to respond to a mock RFP for our fictitious company, CheapBooksNStuff.com. To determine CheapBooksNStuff's needs, we honed in on issues that any e-business would face.

Modeled as a new direct-sales e-business with an operate-in-the-red investment philosophy rivaling Amazon.com's, CheapBooksNStuff's infrastructure is riddled with single points of failure and questionable network design choices. The company is seeking a solution that will fix all its network problems by adding redundancy and scalability, but it's not eager to discard its core equipment. Therefore, the winning proposal must incorporate CheapBooksNStuff's existing infrastructure wherever feasible.

CheapBooksNStuff's e-business infrastructure consists of a West Coast data center; an identical East Coast facility will come online in the near term. Additional data centers are planned for European and Asian markets and are intended to solidify CheapBooksNStuff's Internet and Web presence there. The West and East Coast layout consists of a predominantly Gigabit Ethernet network with one T3 connection to the Internet. The company plans to add a backup T3 connection, provisioned by another ISP. Each site comprises 15 Web servers containing mirrored content and six database servers with unique data in each database.

CheapBooksNStuff's current load-balancing solution relies on round-robin DNS and does not prevent revenue loss from downed Web servers and black-holed users. This solution has been deemed inadequate and must be replaced.

Furthermore, CheapBooksNStuff needs a way to intelligently direct incoming requests to the most appropriate Web site. It's asking for solutions that will let it create and maintain a seamless global Web-site presence while redirecting users based on site load and network proximity of clients.

CheapBooksNStuff is also considering Web-content switching or URL load-balancing as a means of better utilizing its existing Web servers. These products examine HTTP requests and use them to direct incoming requests to servers. However, these methods also involve some heavy processing and resource overhead before the load-balancing can occur.

The goal is to direct more CPU-intensive traffic to larger servers and vice versa. QoS (Quality of Service) and caching technologies are being considered as well, as ways of improving site response and performance. A back-end frame relay connection is in place and used as part of a homegrown content-management system to synchronize Web and database content at each PoP (point of presence).

Last, CheapBooksNStuff would like any prospective solution to coexist with multiple ISPs and thus react to possible changes in the routing of Internet traffic. Because CheapBooksNStuff has not yet addressed the specifics of the second ISP, we gave no additional details regarding routing and peering protocols.

We asked each vendor to provide a solution that improves site performance and response time, eliminates single points of failure and individually addresses each item listed above. We also indicated that CheapBooksNStuff's e-business is expecting a flash of site traffic after a 30-second Super Bowl advertisement scheduled for January 2001.